The problem occurs in JFC 1.1 as well in 1.1.1 beta1.
A JCombobox gets clipped when there is not enough space in a JApplet below the
JComboBox.
This naive behaviour has to be expected since the light weight component can not exceed the space of the surrounding heavy one.
This deficiency might be overcome in most of the cases if the JComboBox would
use the space above!
This should be fairly easy since >someone< figures out that the JComboBox would
exceed the physical limit of a monitor and the JComboBox nicely unfolds in the
available space above.
The bug is that it doesn't do the trick for the border of a heavy weight component !

The defect can be demonstrated easily with the files in the attachment:
japplet1.html, JApplet1.class, JApplet1.java.
All three files should be located in the same directory a swingall.jar file
from JFC 1.1 or JFC1.1.1 beta1 has to be added manually.

A JDK 1.1 appletviewer being called with the argument japplet1.html is needed to exercise the bug.

Step 1.: $appletviewer japplet1.html
The appletviewer will popup in the uper left corner of the monitor
Step 2.: Click on the combobox >United States<
The selection list will not fall down since the JComboBox hass not
enough pixel space. This feature is ugly but expected...
Step 3.: Enlarge appletviewer window at the lower end and click the combobox
Proof of concept: The combobox unfolds nicely as long as there is
enough pixel space.
Step 4.:
a.) Resize window to it's original size (which is to small!)
b.) Move the entire applet viewer to the lower end of the monitor.
The lower border of the appletviewer hasn't even to touch
the lower end of the monitor. It just has to be far enough
in order to make the selection list hit the end of the screen.
Step 5.: Click on the combobox:
Voila! QED! The selection list appears in it's full beauty above
the combo box !

This behaviour should take place whenever the selection box would suffer a
>hangover< beyond the border of the heavyweight component!

Most swing application using a dynamic layout should benefit from this bugfix,
since they would behave in a more tolerant way ...